Middos, Chapter 5, Mishnah 2. Perek five is given over to the dimensions of the Azarah, the courtyard of the Beit Hamikdash. The opening mishnah supplied its general measurements, among them the 135 amot that span the courtyard from its northern edge to its southern one. Our mishnah takes that single number apart, piece by piece, so that we can picture everything that stood along that line.
The text begins: "Mitzfon ledarom me'ah ushloshim vechamesh." The span reaching from the northern side to the southern side came to 135 amot, and the mishnah now itemizes it.
The mizbe'ach and its ramp
"Hakevesh vehamizbe'ach shishim ushnayim": between them, the altar together with the ramp leading up to it accounted for 62 amot. The figure looks puzzling at first, since the mizbe'ach measured 32 amot and the kevesh measured 32 amot as well, which should total 64. The resolution lies in an overlap: the lower end of the kevesh sat above the yesod, the base of the altar, for a stretch of two amot, so that the two structures together covered only 62 amot of floor.
The rings for shechitah
"Min hamizbe'ach lataba'ot shemoneh amot": eight amot separated the northern face of the altar from the nearest row of rings. The taba'ot were rings sunk into the pavement; the head of an animal was set into a ring so that the animal would be held in place during shechitah.
"Mekom hataba'ot esrim ve'arba," the area of the rings themselves measured 24 amot, counting from the first row to the last. There were four rows of six rings each. Spaced eight amot apart, the three gaps between the four rows account for the 24 amot.
The tables
"Min hataba'ot lashulchanot arba," from the last row of rings until the tables was another four amot. North of the rings stood eight tables, used for rinsing out and cleaning the korban after the shechitah. And from the first table to the last was another four amot.
Observe that in running through these figures the mishnah passes over the width of the tables themselves. They were set out in two rows of four. Each table measured an amah and a half across, and one amah of clear floor lay between the two rows: an amah and a half, then an amah, then another amah and a half. Four amot of the courtyard's breadth therefore belonged to the tables.
The pillars and the northern wall
"Min hashulchanot velananasin arba": a further four amot ran between the tables and the line of low posts. These nanasin already appeared in the third perek: short pillars fitted with hooks, used in flaying and preparing the korban.
"Min hananasin lakotel ha'azarah shemoneh amot": eight amot stretched between those posts and the northern wall of the courtyard. Here again the mishnah is counting only bare floor, leaving the thickness of the posts out of the reckoning for the moment.
Balancing the account
Let us add the figures the mishnah has supplied: 62, 8, 24, 4, 4, 4 and 8, which come to 110 amot. Since the courtyard's north-south span was 135, twenty-five amot are missing from the list. Four of them belong to the tables, as explained, leaving 21 amot still unplaced.
The closing clause tells us where those 21 belong: "Vehamotar bein hakevesh lakotel umekom hananasin." They divide into two equal halves. One portion, ten and a half amot, was the open pavement lying below the foot of the kevesh until one reached the wall on the southern side of the courtyard. The other ten and a half amot were filled by the nanasin themselves, whose width the mishnah had not yet entered into its tally. The 135 amot spanning the Azarah north to south are now fully accounted for.